| 1. |
- Eltahir, Mohamed, et al.
(author)
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An Adaptable Antibody-Based Platform for Flexible Synthetic Peptide Delivery Built on Agonistic CD40 Antibodies
- 2022
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In: Advanced Therapeutics. - : Wiley. - 2366-3987. ; 5:7
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Journal article (peer-reviewed)abstract
- The agonistic potentials of therapeutic anti-CD40 antibodies have been profiled in relation to antibody isotype and epitope specificity. Still, clinical impact relies on a well-balanced clinical efficacy versus target-mediated toxicity. As CD40-mediated immune activation must rely on a combination of stimulation of antigen-presenting cells (APCs) alongside antigen presentation, for efficient T cell priming, alternative approaches to improve the therapeutic outcome of CD40-targeting strategies should focus on providing optimal antigen presentation together with CD40 stimulation. Herein, a bispecific antibody targeting CD40 as a means to deliver cargo (i.e., synthetic peptides) into APCs through a non-covalent, high-affinity interaction between the antibody and the cargo peptide, further referred to as the Adaptable Drug Affinity Conjugate (ADAC) technology, has been developed. The ADAC platform demonstrated a target-specific CD4+ and CD8+ T cell expansion in vitro and significantly improved peptide-specific CD8+ T cell proliferation in vivo. In addition, the strategy dramatically improved the in vitro and in vivo half-life of the synthetic peptides. Future applications of ADAC involve pandemic preparedness to viral genetic drift as well as neoepitope vaccination strategies where the bispecific antibody is an off-the-shelf product, and the peptide antigen is synthesized based on next-generation sequencing data mining.
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| 2. |
- Lindqvist, Annika, 1983-, et al.
(author)
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Exploring Factors Causing Low Brain penetration of the Opioid Peptide DAMGO through Experimental Methods and Modeling
- 2016
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In: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 13:4, s. 1258-1266
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Journal article (peer-reviewed)abstract
- To advance the development of peptide analogues for improved treatment of pain, we need to learn more about the blood brain barrier transport of these substances. A low penetration into the brain, with an unbound brain to blood ratio, K-p,K-uu, of 0.08, is an important reason for the lack of effect of the enkephalin analogue DAMGO (H-Tyr-D-Ala-Gly-MePhe-Gly-ol) according to earlier findings. The aim of this study was to investigate the role of efflux transporters, metabolism in the brain, and/or elimination through interstitial fluid bulk flow for the brain exposure of DAMGO. The in vivo brain distribution of DAMGO was evaluated using microdialysis in the rat. Data were analyzed with population modeling which resulted in a clearance into the brain of 1.1 and an efflux clearance 14 mu L/min/g_brain. The efflux clearance was thus much higher than the bulk flow known from the literature. Coadministration with the efflux transporter inhibitors cyclosporin A and elacridar in vivo did not affect K-p,K-uu. The permeability of DAMGO in the Caco-2 assay was very low, of the same size as mannitol. The efflux ratio was <2 and not influenced by cyclosporin A or elacridar. These results indicate that the well-known efflux transporters Pgp and Bcrp are not responsible for the higher efflux of DAMGO, which opens up for an important role of other transporters at the BBB.
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| 3. |
- Lindqvist, Annika, 1983-, et al.
(author)
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In vivo Functional Evaluation of Increased Brain Delivery of the Opioid Peptide DAMGO by Glutathione-PEGylated Liposomes
- 2016
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In: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 33:1, s. 177-185
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Journal article (peer-reviewed)abstract
- Purpose:The purpose of this study was to evaluate formulation factors causing improvement in brain delivery of a small peptide after encapsulation into a targeted nanocarrier in vivo.Methods:The evaluation was performed in rats using microdialysis, which enabled continuous sampling of the released drug in both the brain (striatum) and blood. Uptake in brain could thereby be studied in terms of therapeutically active, released drug.Results:We found that encapsulation of the peptide DAMGO in fast-releasing polyethylene glycol (PEG)ylated liposomes, either with or without the specific brain targeting ligand glutathione (GSH), doubled the uptake of DAMGO into the rat brain. The increased brain delivery was observed only when the drug was encapsulated into the liposomes, thus excluding any effects of the liposomes themselves on the blood-brain barrier integrity as a possible mechanism. The addition of a GSH coating on the liposomes did not result in an additional increase in DAMGO concentrations in the brain, in contrast to earlier studies on GSH coating. This may be caused by differences in the characteristics of the encapsulated compounds and the composition of the liposome formulations. Conclusions:We were able to show that encapsulation into PEGylated liposomes of a peptide with limited brain delivery could double the drug uptake into the brain without using a specific brain targeting ligand.
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| 4. |
- Lindqvist, Annika, 1983-, et al.
(author)
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Pharmacokinetic Considerations of Nanodelivery to the Brain : Using Modeling and Simulations to Predict Outcome of Liposomal Formulations
- 2016
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In: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 92, s. 173-182
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Journal article (peer-reviewed)abstract
- The use of nanocarriers is an intriguing solution to increase the brain delivery of novel therapeutics. The aim of this paper was to use pharmacokinetic analysis and simulations to identify key factors that determine the effective drug concentration-time profile at the target site in the brain. Model building and simulations were based on experimental data obtained from the administration of the opioid peptide DAMGO in glutathione tagged PEGylated liposomes to rats. Different pharmacokinetic models were investigated to explore the mechanisms of increased brain delivery. Concentration time profiles for a set of formulations with varying compound and carrier characteristics were simulated. By controlling the release rate from the liposome, the time profile and the extent of brain delivery can be regulated. The modeling did not support a mechanism of the liposomes passing the brain endothelial cell membrane in an intact form through endocytosis or transcytosis. The most likely process was found to be fusion of the liposome with the endothelial luminal membrane. The simulations revealed that low permeable compounds, independent on efflux, will gain the most from a nanocarrier formulation. The present model based approach is useful to explore and predict possibilities and limitations of carrier-based systems to the brain.
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| 5. |
- Lindqvist, Annika, 1983-
(author)
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Quantitative Aspects of Nanodelivery Across the Blood-Brain Barrier : Exemplified with the Opioid Peptide DAMGO
- 2015
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Doctoral thesis (other academic/artistic)abstract
- The use of nanocarriers is an intriguing approach in the development of efficacious treatment for brain disorders. The aim of the conducted research was to evaluate and quantify the impact of a liposomal nanocarrier formulation on the brain drug delivery. A novel approach for investigating the blood-brain barrier transport of liposomal DAMGO is presented, including in vivo microdialysis in rat, a high quality LC-MS/MS bioanalytical method and pharmacokinetic model analysis of the data. Factors limiting the brain distribution of the free peptide DAMGO were also investigated. Microdialysis, in combination with plasma sampling, made it possible to separate the released drug from the encapsulated and to quantify the active substance in both blood and brain interstitial fluid over time.The opioid peptide DAMGO entered the brain to a limited extent, with a clearance out of the brain 13 times higher than the clearance into the brain. The brain to blood ratio of unbound drug was not affected when the efflux transporter inhibitors cyclosporine A and elacridar were co-administered with DAMGO. Nor was the transport affected in the in vitro Caco-2 assay using the same inhibitors. This indicates that DAMGO is not transported by P-glycoprotein (Pgp) or breast cancer resistant protein (Bcrp). The blood-brain barrier transport was significantly increased for DAMGO when formulated in liposomes, resulting in 2-3 fold higher brain to blood ratio of unbound DAMGO. The increased brain delivery was seen both for glutathione tagged PEGylated liposomes, as well as for PEGyalted liposomes without specific brain targeting. The improvement in brain delivery was observed only when DAMGO was encapsulated into the liposomes, thus excluding any effect of the liposomes themselves on the integrity of the blood-brain barrier. Modeling of the data provided additional mechanistic understanding of the brain uptake, showing that endocytosis or transcytosis of intact liposomes across the endothelial cell membranes were unlikely. A model describing fusion of the liposomes with the luminal membrane described the experimental data the best.In conclusion, the studies presented in this thesis all contribute to an increased understanding of how to evaluate and improve brain delivery of CNS active drugs and contribute with important insights to the nanocarrier field.
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| 6. |
- Nordeng, Hedvig, et al.
(author)
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Transfer of cetirizine/levocetirizine into human breast milk and estimation of drug exposure to infants through breastfeeding : A human lactation study from the ConcePTION project
- 2024
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In: Basic & Clinical Pharmacology & Toxicology. - : John Wiley & Sons. - 1742-7835 .- 1742-7843. ; 134:1, s. 153-164
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Journal article (peer-reviewed)abstract
- Data on drug transfer into human breast milk are sparse. This study aimed to quantify concentrations of cetirizine and levocetirizine in breast milk and to estimate drug exposure to infants. Breastfeeding women at least 8 weeks postpartum and using cetirizine or its pure (R)-enantiomer levocetirizine were eligible to participate. Breast milk samples were collected at six predefined times during a dose interval (0, 2, 4, 8, 12 and 24 h after drug intake) at steady state. Infant drug exposure was estimated by calculating the absolute infant dose (AID) and the weight-adjusted relative infant dose (RID). In total, 32 women were eligible for final inclusion, 31 women using cetirizine and one woman using levocetirizine. Means of the individual maximum and average cetirizine milk concentrations were 41.0 and 16.8 mu g/L, respectively. Maximum concentrations occurred on average 2.4 h after intake, and the mean half-life in milk was 7.0 h. Estimated AID and RID for cetirizine in a day were 2.5 mu g/kg and 1.9%, respectively. The corresponding values for levocetirizine were 1.1 mu g/kg and 1.9%. No severe adverse events were reported. Our findings demonstrate that the transfer of cetirizine and levocetirizine into breast milk is low and compatible with breastfeeding.
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| 7. |
- Wegler, Christine, et al.
(author)
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Simple and rapid quantification of cetirizine, venlafaxine, and O-desmethylvenlafaxine in human breast milk, and metformin in human milk and plasma with UHPLC-MS/MS
- 2022
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In: Journal of chromatography. B. - : Elsevier. - 1570-0232 .- 1873-376X. ; 1205
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Journal article (peer-reviewed)abstract
- The majority of women have health problems that require medication after giving birth. Complications such as allergies, postpartum depression, and diabetes are often treated with drugs such as cetirizine, venlafaxine, and metformin, respectively. These treatments are considered safe during lactation, but information of the transfer of drugs to breast milk and possible effects on the infant is scarce. Therefore, this needs to be systematically investigated in larger populations. To enable the determination of drug transfer, we here describe the validation of two rapid, sensitive, and high-throughput analysis methods for 1) simultaneous quantification of cetirizine, venlafaxine, and O-desmethylvenlafaxine in human breast milk, and 2) metformin in human breast milk and plasma. In both methods, a simple protein precipitation protocol with acetonitrile and benchtop-centrifugation was used prior to compound analysis with liquid-chromatography tandem mass spectrometry. The methods had linear ranges between 0.39 - 194.5 ng/mL for cetirizine, 0.28 - 138.7 ng/mL for venlafaxine, 0.26 - 131.7 ng/mL for O-desmethylvenlafaxine, in milk, and 0.65 - 193.7 ng/mL for metformin in both milk and plasma. Intra-run and inter-run precision and accuracy were < 9% for cetirizine, venlafaxine, and O-desmethylvenlafaxine in milk, and < 7% for metformin in milk and plasma. Cetirizine was measured to median milk concentrations of 13 ng/ mL (range: 0.65 - 65 ng/mL) in 228 donor samples from breast-feeding women.
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